Mercedes introduced its first luxury SUV, the ML, nearly a decade ago. Now in its second generation, the model now known as the M-Class has evolved from a truck-based body-on-frame SUV to a carlike, easy-to-handle utility vehicle. After various suspension revisions, safety improvements and equipment upgrades over the years, the M-Class emerges freshly updated for 2009 at a time when gas-guzzling midsize and large SUVs teeter on the brink of extinction.

On the inside, the 2009 Mercedes-Benz M-Class gets a revised, easier-to-use version of Mercedes' COMAND interface, which includes Bluetooth phone connectivity, an auxiliary jack and an in-dash six-CD/DVD changer. An optional, upgraded version of the COMAND system adds a plethora of the latest technology features, such as a voice-activated hard-drive-based navigation system with 4GB of music storage, satellite radio, HD radio, Zagat restaurant reviews and an iPod connector.

Those concerned with fuel economy may take interest in the new ML320 Bluetec. Replacing last year's ML320 CDI, the Bluetec has a 3.0-liter V6 that, thanks to a special additive, burns diesel more cleanly than previous diesel engines. The Bluetec is 50-state legal (the CDI wasn't) and its fuel economy is 17 percent better than the EPA ratings for the regular ML350. The Bluetec model has less oomph for highway passing and costs $1,500 more, but it's certainly an interesting alternative to the regular ML350.

Overall, the 2009 M-Class retains the characteristics consumers associate with Mercedes-Benz: quality, luxury, prestige and state-of-the-art safety. Naturally, there are other choices in the $50,000 luxury midsize SUV segment. Nearly every competitor has been updated (or introduced) in the past year or two, including the Acura MDX, Audi Q7 and BMW X5, along with the Lexus RX 350, Porsche Cayenne and Volkswagen Touareg 2. And unlike some others in the segment, the M-Class doesn't offer a third-row seat. Adding a bunch of options can raise the ML's price to uncomfortable levels as well. Still, the 2009 Mercedes-Benz M-Class should prove a fine choice for those looking for the latest gadgets and comfortable seating for five in a midsize luxury SUV.

The 2009 Mercedes-Benz M-Class is a five-passenger luxury crossover SUV available in four trim levels: ML320 Bluetec, ML350, ML550 and ML63 AMG. The ML320 Bluetec and ML350 are similarly equipped, with 19-inch wheels (although the design varies between the two models), a sunroof, dual-zone automatic climate control, power front seats, cruise control, a 60/40-split-folding rear seat, the COMAND interface, Bluetooth and an eight-speaker audio system with a six-CD/DVD changer and an auxiliary jack.

The ML550 adds AMG-style bumpers and 19-inch wheels, along with brushed aluminum running boards and roof rails. The ML63 AMG features special interior and exterior styling details, as well as a sport-tuned air suspension, 20-inch wheels, upgraded brakes, bi-xenon adaptive headlights, corner-illuminating foglights, leather upholstery, a sport steering wheel with paddle shifters, and ultra-supportive heated and ventilated front sport seats.

Options for the ML320, ML350 and ML550 include the Premium 1 Package, which adds a power liftgate, a rearview camera, a 115-volt AC power outlet and an upgraded version of the COMAND system with a hard-drive-based navigation system that has voice activation, real-time traffic updates and 4GB of music storage. This package also comes with a premium Harman Kardon Logic 7 surround-sound audio system and satellite radio, HD radio and an iPod connector. The Premium 2 Package features everything found in the Premium 1 Package plus a park assist system, power-folding side mirrors, auto-dimming mirrors, front-seat memory settings and keyless ignition/entry. Leather seating and a Heating Package (heated front and rear seats, as well as a heated steering wheel) are available for all trim levels except the M63 AMG.

Stand-alone options include an air suspension with adaptive damping, adaptive bi-xenon headlights, rear climate controls and a rear-seat entertainment system. The ML63 AMG can also get 21-inch wheels and heated rear seats.

The 2009 M-Class comes with a choice of four engines, and all come standard with a seven-speed automatic transmission. Apart from the ML350 rear-wheel-drive model, every M-Class trim level has all-wheel drive. The ML320 Bluetec has a 3.0-liter turbodiesel V6 rated at 210 horsepower and a stout 398 pound-feet of torque. Fuel economy ratings for this model are 18 mpg city/24 mpg highway and 20 mpg combined. The ML350 has a 3.5-liter V6 that makes 268 hp and 258 lb-ft of torque, and gets an estimated 15 city/20 highway and 17 mpg combined. The rear-wheel-drive ML350 gets 1 mpg better across the board.

For more exhilarating performance, the ML550 boasts a 5.5-liter V8 that pumps out 382 hp and 391 lb-ft of torque. But it's no surprise that power comes at the expense of fuel economy. It's rated at 13/18/15 mpg. The top power plant in the M-Class lineup, the ML63 AMG's 6.3-liter V8, makes an awe-inspiring 503 hp and 465 lb-ft of torque -- enough to propel this SUV from zero to 60 mph in just 4.7 seconds. It's rated at 11/15/12 mpg.

Antilock disc brakes with brake assist, traction and stability control, hill descent/ascent control and a full complement of airbags (front-seat side and full-length side curtain) are all standard. In government crash tests, the 2009 Mercedes-Benz M-Class posted perfect five-star scores in both frontal- and side-impact testing. The Insurance Institute for Highway Safety gave the SUV a top score of "Good" for its protection of occupants in frontal-offset crashes.

Steering is precise on the 2009 Mercedes M-Class, but it doesn't offer much feedback and feels a little dead in the center. There is some body roll around corners, which is to be somewhat expected from a near 5,000-pound AWD SUV, but the M-Class stays predictable and stable on the road. Braking is quite good; a sure-footed pedal and quick response make for confident stopping power.

A warm, upscale character is conveyed throughout the cockpit of the 2009 Mercedes-Benz M-Class, thanks to a combination of wood and aluminum trims. Passenger room is impressive; rear seating offers more than 39 inches of legroom, nearly 6 inches more than the Lexus RX 350 provides. With the rear seats in place, there is a total of 29 cubic feet of luggage space. When the seats are folded flat, that expands to 72 cubes, an average figure for this class of vehicle. A variety of cubbies throughout the cabin, as well as large front cupholders, prove useful on road trips.